A wide variety of sheaths have been developed for use in medical procedures. Sheaths are often used, for example, to access a vessel or artery to allow a surgical procedure to be performed. Sheaths are also used for medical procedures such as angioplasty or stenting that utilize catheters.
In practice, an introducer sheath is generally inserted into the patient's vasculature using the modified Seldinger technique. In the Seldinger technique, a needle is first inserted into the vessel and a guide wire then follows through the needle. Next, the needle is removed and a sheath/dilator combination is advanced over the guide wire. The dilator expands the puncture in the vessel to a size suitable to receive the distal end of an introducer sheath. After the distal end of the sheath is disposed within the vessel, the dilator and guide wire are removed, thereby allowing access to the vessel lumen or other body lumen via the inserted introducer sheath. Thus, the introducer sheath may facilitate introducing various devices into the vessel, while minimizing trauma to the vessel wall and/or minimizing blood loss during a procedure.
Conventionally, introducer sheaths include at least three components: a sheath portion, a hub, and a hemostasis valve disposed within the hub. A suitable example of such an assembly is shown in U.S. Pat. No. 5,807,350, which shows an introducer sheath having a construction similar to that described above, the entirety of which is hereby incorporated by reference.
Upon completion of a procedure, the devices and introducer sheath are typically removed from the patient, leaving a puncture site in the vessel wall. Traditionally, external pressure is applied to the puncture site until clotting and wound sealing occur, however, the patient must remain bedridden for a substantial period of time after clotting to ensure closure of the wound. This procedure, however, may be time consuming and expensive, requiring as much as an hour of a physician's or nurse's time. It is also uncomfortable for the patient, and requires that the patient remain immobilized in the operating room, catheter lab, or holding area.
The time required for clotting is typically increased because patients undergoing catheterization or stenting procedures are generally given systemic anticoagulant drugs to prevent or forestall clot formation. The use of systemic anticoagulants may be medically necessary for many reasons. One important consideration calling for the use of anticoagulants is the risk of embolism (i.e., venous or arterial blockage) if a clot forms at the puncture site and that clot subsequently dislodges and lodges elsewhere in the patient's circulatory system. Regardless of whether the patient is given systemic anticoagulants, there is also a risk of the hematoma formation at or near the puncture site due to bleeding from the tissue around the access site and the opening in the lumen itself. A hematoma at or near the puncture site can cause the patient extreme discomfort and increase recovery time.
As such, various apparatuses and methods have been suggested for percutaneously sealing a vascular puncture by occluding the puncture site. Apparatuses and methods for sealing vascular punctures include, but are not limited to, use of sutures, clips, plugs, and combinations thereof.
For example, U.S. Pat. No. 5,304,184, issued to Hathaway et al. describes percutaneously suturing the puncture site. Alternatively, U.S. Pat. No. 5,674,231, issued to Green et al., discloses a deployable loop that may be advanced through a sheath into a vessel. The loop is intended to resiliently expand to engage the wall of the vessel, thereby closing the puncture. The sheaths disclosed herein can also be used with a vessel closure device, such as those shown in U.S. Pat. No. 6,197,042 and pending U.S. patent application Ser. No. 10/638,115 filed Aug. 8, 2003 entitled “Clip Applier and Methods.” In another example, U.S. Pat. Nos. 5,192,302 and 5,222,974, issued to Kensey et al., describe the use of a biodegradable plug that may be delivered through an introducer sheath into a puncture site. Each of the above referenced patents and applications are incorporated herein in their entireties by reference.